With a higher demand on storage applications, users need to perform data protection in an online manner, and a snapshot is one of the effective methods for preventing a data loss using an online storage device. The snapshot refers to an instant consistency image of data of a production volume. The so-called production volume refers to a logical unit data volume that provides data storage and access space for basic service applications. By using the data snapshot technology, an instant consistency image (namely, a snapshot) that is of data of a production volume and completely available may be obtained in an instant, and occupies relatively less storage space. After a snapshot is created, the snapshot and a production volume may be simultaneously accessed, thereby not affecting service continuity of the production volume.
In an existing snapshot data processing method, when data of a logical unit in a production volume is written, copy-on-write and mapping entry insertion need to be performed on the data of the same logical unit for each snapshot in the same production volume. Assuming that one production volume has multiple activated snapshots, copy-on-write and mapping entry insertion need to be performed for multiple times on data of a same logical unit for the multiple snapshots of the same production volume.
Therefore, the existing snapshot data processing method has a problem of low efficiency.